Peening hammer



2 Sheets-Sheet l INVENTOR.

ATTORNEY Dec. 11, 1945. s. KOTOWICZ PEENING HAMMER Filed June 21, 1943 m 3 mm;

7 Dec. 11, 1945. s. KOTOWICZ 2,390,795 PEENfNG HAMMER Filed June 21, 1943 2 Sheets-Sheet 2 i I 7 C 6 v BBOZZ 1 E J j is, Z d] &\ xxx IN VE N TOR.

ATTORNEY.

Patented Dec. 11, 1945 UNITED STATES PATENT OFFICE 4 Claims.

This invention relates to power-operated peening hammers.

The object of the invention is to provide a power-operated peening hammer designed and adapted for use in straightening or truing up metal plates and bars of hard resistant metal, as the liners of brick molding machines.

To effect the object thereof, a machine embodying my invention and improvements comprises the various features, combinations of features, and details of construction hereinafter described and claimed.

In accompanying drawings, in which the invention is fully illustrated Fig. 1 is a side elevational of a peening machine embodying my invention and improvements;

Fig, 2 is a sectional View, partly in elevation. the section being taken substantially on line 2-2 of Fig. 1;

Fig. 3 is a sectional elevation substantially on the line 33 of Fig. 2; and

Figs, 4 and 5 are enlarged fragmentary detail views of one form of peen hammer.

Describing the invention with reference to the drawings, a machine embodying my invention and improvements comprises a frame consisting of a massive bed portion A and an upright standard B supported at the rear end of said base portion.

For reasons presently apparent, the base portion A is made in two portions comprising a base portion proper a adapted to be secured in fixed position to a bench or other support and a bed or table a movably supported on the fixed portion a so as to be adjustable thereon towards and from the standard B, in a manner familiar in planer construction. As shown, see particularly Fig. 3, the bed or table a is adapted to be adjusted endwise by means of a screw a which engages a hole or opening formed in a boss a formed on the underside of the bed or table a, the base portion a being provided with a hole or opening a to receive the screw a and boss (1 The screw a is rotatably mounted in a bearing formed in the fixed portion a of the base at the front end of the opening a and is secured against endwise movement by means of a shoulder thereon adjacent its outer end, and a pin a secured in said screw between which and the face of the bearing for said screw a washer a is inserted. The screw a is adapted to be turned by means of a handle wheel a secured to its outer end, in a usual manner.

In the preferable construction shown, the standard B consists of a cylindrical post I), the

lower end of which has screw-threaded engagement with a hole or opening in the fixed portion a of the base, and a head designated as a whole B, rotatably mounted on the upper end of the post I), on which the operative parts of the machine are mounted.

To provide for raising and lowering the head B and thus the hammer and other parts operatively mounted thereon, as presently described, the thread connecting the post b to the fixed portion a of the base is of relatively fine pitch, say sixteen threads to the inch, and said post is adapted to be secured in different adjusted positions, corresponding to the desired vertical adjustment of the head B by means of a set-screw I). Also, to provide for adjusting the head B axially, the hole in said head which receives the upper end of the post b is fitted to said post so that the head B will turn freely thereon, and said head is adapted to be secured in different adjusted positions by means of a set-screw b The operative parts of the machine comprise a hammer designated as a whole C, consisting of a handle I and a head 2. The hammer handle I is pivoted at 3 in a slot d formed in the head portion B of the standard, the free end of said handle extending over the bed portion a of the base portionA of the machine, and the hammer head 2 being secured in the outer end of said handle.

In operation, the work to be straightened, as a plate indicated at d, Figs. '3 and 4, is supported upon the adjustable bed portion a of the base A of the machine and is straightened or trued by subjecting it to a succession of light, tapping blows of the hammer C, the plate or other work d being shifted from place to place on the bed a to cause the hammer head 2 to strike the same in proper position to straighten it, as the experience of the operator indicates is necessary. The vertical adjustability of the standard B through its screw-threaded engagement with the fixed portion a of the base provides means for varying the adjustment of the hammer 2 relative to the bed a and work d, to adapt the machine for working on plates or pieces of different thickness, so that it will always impinge upon the same substantially at right angles. Also, the axial adjustability of the,standard B provides for adjusting the hammer head 2 so that it will be substantially in line with an edge of the bed a, thus providing for straightening plates which have a plurality of high spots, this being rendered possible by shifting the plate to bring said high spots in line with an edge of the bed a and at the same time directly below the hammer head 2. With this relation, it is obvious that said high spots may be separately straightened by shifting the plates to subject them successively to the action of the hammer head 2 and at the same time tilting the plate slightly so that only the high spot on which the hammer is operating at a given time will rest against the bed a.

In operation, oscillation is adapted to be imparted to the hammer C to cause the hammer head 2 to execute a succession of blows on the work at by means of a rotatable cam which cooperates with a relatively fixed part of the hammer handle to raise the hammer head 2 and then to release the same substantially at the top of its stroke, and a spring or springs applied to the hammer handle adapted to throw the hammer down upon the work with a blow of desired force.

As shown, the hammer is adapted to be raised by a cam secured to a driven shaft (Lsaid cam cooperating with a relatively fixed part of the hammer handle, as shown an anti-friction roller I mounted to turn on a fixed axis on the hammer handle. The cam 5 and roller I are positioned in the slot 4 in the head B, said cam being provided with a square axial opening adapted to receive a corresponding square portion 8 of the shaft Ii. When the hammer is released by the cam 5, it is adapted to be thrown down into contact with the work 11 by a suitable spring; as shown.

Rotation is adapted to be imparted to the cam shaft 6 and thus to the cam 5, by driving connection with a suitable source of power. In the preferable construction shown, said cam shaft is driven by an electrical motor II, a pinion I2 secured to the armature shaft of which intermeshes with a gear I3 secured to the cam shaft. Also, to render the machine self-contained, the motor I I is mounted on a bracket Hi forming part of the head B on which the cam 5 and associated parts are mounted. Uniformity and smoothness of operation are secured by means of a fiy-wheel I5 secured to the cam shaft 6, in a usual manner, and the operating shaft 6 and attached parts are carefully balanced to prevent vibration.

To provide for lubricating the cam 5 and antifriction roller 1, thus reducing wear thereof in operation, the front and rear sides of the slot 4 are closed for a distance above the bottom thereof by walls I6 and I1, thus forming a well I 8 at the bottom of said slot, adapted to contain oil, as indicated at I9, through which the eccentric portion of the cam will pass as the cam rotates, which will operate in an obvious manner to keep both the cam and the opposed cooperating part on the hammer handle I well lubricated at all times, in the manner desired.

Prior to my invention, so far as I have any knowledge, the straightening of bars and plates by peening has been effected b means of peen hammers, the striking portions of which are shaped to indent, usually being either straight, pointed, conical, hemi-spherical, or wedge-shaped, the peening operation consisting in striking the pieces to be straightened a succession of light, tapping blows with a peen hammer manipulated by hand. This is a slow, monotonous, tiresome, and expensive process, and the primary object of the present invention may be described as being the provision of a machine which is constructed and arranged to simulate the blow of peening hammersmanipulated by hand, which will operate at high speed and will have relatively very large capacity as compared with previous hand methods and which will effect a corresponding economy in peening process. To illustrate, a peening machine embodying my invention and improvements is designed to execute from 400 to 600 strokes per minute, as compared to about strokes per minute, which is approximately the maximum number of strokes 0r blows that can be effectively executed by hand over or durin any considerable period of time.

The hammer head 2 is quite light, a desirable weight for usual peening purposes being from 1 /2 to 2 pounds, peening being effected by raising the hammers a short distance above the piece tobe straightened--a usual distance for most purposes being from 2 to 4 inchesand permitting it to drop upon the work, impelled bygravity only. As a result, it is obvious that, in the case of my improved machine, operating in simulation of hand peening at the rate of from 400 to 600 strokes, or blows a minute, the cam 5, having raised and released the hammer, will again engage the antifriction roller I or other cooperating part on the hammer handle on its next successive rotation before the hammer head 2, fallin by gravity, can contact With the work. Thus the machine would operate idly and would do no work at all. In accordance with my invention, I prevent such idle operation by so calibrating the springs 9 and ID, or other springs employed for throwing the hammer down, that the action of gravity in the operation will be practically eliminated, said springs operating first to overcome the inertia of the hammer as soon as it is released by the cam 5, and then throwing it down with such velocity that it will strike the work before the cam 5 engages the cooperating part of the hammer handle on its succeeding stroke.

To provide for using hammer heads 2 of different weights and having-striking ends of diiferent shapes, if desired, to adapt the machine for doing difierent kinds of work, said hammer head is preferably made as a separate part and is detachably secured to the-hammer handle I. .As shown, the means for securing hammer heads 2 to the handle I consists of a shank 26 formed on the hammer head, which is adapted to engage a corresponding hole formed in a boss 2i at the free end of the hammer handle. Said hammer head is adapted to be secured to the hammer handle I by means of a nut threaded to the shank 2|] after it has been inserted through the hole in the boss 2|. Also, washers 22 are inserted between the upper end of the hammer head 2 and the nut threaded to the upper end of the shank 20 and th faces on the boss 2| opposed thereto, respectively. By provid-- ing a number of these washers 22 so that one or more thereof may be inserted either above or below the boss on the hammer handle in which the bearing for the shank 20 is formed, it is obvious that the position of the hammer head 2 relative to .the work d may be adjusted, within considerable limits, relative to the Work without varying the operative stroke of the machine.

This machine is especially designed for straightening high tempered steel, flat plates, bars or the like which cannot be straightened from their convex sides as where of soft steel. Ordinarily such operations on high tempered steel must be done from its concave side. Flat steel should be lightly tapped with a wedge-shaped hammer. The hammer should be made from well hardened tool steel, but not too hard to avoid cracking at the edges. The hammer should be of blunt wedged shape and not sharp enough to mark the steel plates. The front spring can be hooked to the hammer handle at the upper end toward the front. The lift of the hammer from the work may be very slight, or greater as the character of the work requires. The force of the hammer blow does not depend so much on the extent of the lift from the Work as on the strength of the strikes. When the hammer is low the speed can be increased accordingly, thus increasing the momentum of the blow of the hammer.

The machine can be operated with pulleys or gears as desired. The speed should be adjusted so that the hammer will strike the work every time after being raised by the cam. When the hammer is raised a short distance from the work, the speed can be increased proportionately; and when the hammer is raised a greater distance from the work, the speed should be proportionately decreased. Thus if the hammer is adjusted a great distance from the work, the speed should be low and when a short distance from the work the speed should be high. For delicate work, the hammer should be adjusted close to the work.

The switch or button for starting or stopping the motor is best controlled by the foot from a sitting position for straightening small pieces. A plate or bar should be slid under the hammer and at the same time felt with the finger tips. When it appears straight, the operation should be stopped and the plate taken in the palm of the left hand and a straight edge applied with the right hand. If light appears under the straight edge, the straightening operation should be repeated until the plate is perfectly straight.

The machine should be made according to the size of the work to be done. For small work, a small machine should be provided, and for larger work a proportionately larger machine.

I claim:

1. In a peening hammer, the combination of a work supporting base, a standard supported thereon comprising a head portion freely rotatable on a Substantially upright axis, an operating shaft mounted on said standard to extend substantially across said axis, a flywheel on said shaft On one side of said axis, a motor on said standard on the other side of said axis and operatively connected with said shaft, a hammer handle pivoted at one end on said standard and extending across said shaft, a cam on said shaft in operative contact with said handle, a hammer head at the free end of said handle, a work supporting table on said base in operative relation with said hammer head; and a spring normally holding said hammer in operative relation with said work table.

2. The construction specified in claim 1 in which the said work supporting table is adjustable toward and away from said axis.

3. The construction specified in claim 1 in which said cam is arranged to dip into an oil well.

4. In a peenin hammer, the combination of a work supporting base, a standard supported thereon comprising a head portion freely rotatable on a substantially upright axis, a hammer proper the handle of which is pivoted to said head portion, a workholding table adjustably mounted on said base in cooperative relation with said hammer, means for adjusting said standard vertically, means for oscillating said hammer rapidly through a short are comprising a motor mounted on and rotating said head portion, and a driving connection between said motor and the hammer handle to raise the head thereof.

STEFAN KOTOWICZ. 

